Reading to a Data Stream

This tutorial describes how to copy data from a database into a data stream.

Introduction

You can read data from the table into a data stream in one chunk or in bits as desired.

Basic procedure

The high level steps to read the data into a data stream are shown here:

Detailed steps

To read the data into a data stream, do the following:

Configure your SQL statement and data stream

As a first step instantiate an object of the RSqlStatement and RSqlColumnReadStream class. Also declare the variables as required.
RSqlStatement myStatement; +TInt err; +TInt myColumnIndex; +RSqlColumnReadStream myStream; +
Clean up the stack.
CleanupClosePushL(myStream);

Read data to a stream

Open the stream for read and associate the data with it.
User::LeaveIfError(myStream.ColumnBinary(myStatement,myColumnIndex));
Determine the column size.
TInt size = myStatement.ColumnSize(myColumnIndex);
Instantiate an object of the RBuf class. Create a buffer of the size of the column. Then read the data into the buffer.
RBuf buf; + buf.CreateL(size); + CleanupClosePushL(buf); + myStream.ReadL(buf,size); +
Close the buffer.
CleanupStack::PopAndDestroy();

Clean up

Close the stream.

CleanupStack::PopAndDestroy();